Apparatus for treating hydrocarbons



J. W. COAST, JR.

APPARATUS FOH'TREATING HYDROCARBONS. APPLICATION'i Ful-ED MAY 5.1917.

1,355,31 1 Patented Oct. 12, 1920.

I1- aa Jaffa 3, @Z4 fm wf UNITED. STATES PATENT OFFICE.-

TOHN W. COAST, JR., OF TULSA, OKLAHOMA, ASSIGNOR T0 THE PROCESS COMPANY,CORPORATION 0F MARYLAND.

APPARATUS FOR TREATING HYDROCARBONS.

Specication of Letters Patent.

Patented Oct. 12, 1920.

Application led May 5, 1917. Serial No. 166,525.

the following is a full, clear, and vexact de-` scription, referencebeing had to the accompanying drawings, forming a part of thisspecification.

My invention relates to improvements 1n apparatus for treatinghydrocarbons, and more particularly to means for cooling hydrocarbonvapor and at the same time heating a body of liquid. The new apparatusmay be used in cracking petroleum hydrocarbons under pressure, to obtaina product known as gasolene, or cracked gasolene. In cracking suchhydrocarbons, the vaporized fractions having relatively high boilingpoints shouldbe condensed and returned to the still for' furthertreatment, and' the fresh charge of oil should be heated before itreaches the still. One of theobjects of my invention is to provide asimple and efficient means for accomplishing these results.

In the preferred form of the invention, a body of relatively cool liquidis maintained in a heat exchanger, and the hot vapor passing from the.still is discharged into this liquid. The hot vapor is permitted to risein the forni of bubbles in the relatively cool liquid, thereby heatingthe liquid and at the same time condensing the previously vaporizedfractions having relatively high boiling points. The body of liquidmaintained in the heat' exchanger may be formed partly by the highboiling point condensate, and partly by a fresh charge of oil. In thisevent, the hot condensate will serve as a heating medium for the freshcharge of oil, and the liquid mixture will be constantly subjected tothe heat of the vapor which bubbles through the liquid. Some' of theliquid will be converted into vapor and pass to a condenser.v The heatedliquid preferably overflows and passes to the still. Some of thisoverflowing liquid is condensate formed by condensing the high boilingpoint fractions, and some of it is preferably a fresh charge of oilwhich has been subjected to the heat of the vapor and condensate.

The drawing is a diagrammatical view of an apparatus embodying thefeatures of my lnvention.

To illustrate the invention, I have shown a crackmg apparatus comprisinga pressure still 1 arranged above a heating chamber 2, a vapor pipe 3leading from the still to a heat exchanger A, a vapor pipe 4 connectingthe heat exchanger to an air cooled reflux condenser 5, and a vapor pipe6 con-v necting said reflux condenser to a water cooled condenser 7,from which the product 1s recovered. A pressure, regulating valve 8, inthe vapor pipe 6, may be regulated to maintain a predetermined pressure1n the refiux condenser, heat exchanger A, and also in the still 1. Aperforated discharge member 9, connected to the vapor pipe 3, issubmerged in a relatively cool body of hydrocarbon liquid containedin areservoir 10. These members 9 and 10 form part of the heat exchanger A,and they are so arranged that the cool liquid will form a liquid-seal inthe vapor line. An overflow pipe 11, provided with a liquidseal, ortrap, 12, leads from the surface of the liquid in the reservoir 10 tothe lower portion of the still 1. A pump 13 may be used to force a freshcharge of relatively cool hydrocarbon oil through a pipe 14 and into thereservoir 10 The new apparatus may be used in cracking various heavyhydrocarbon products resulting from the treatment of crude petroleum,particularly such inexpensive hydrocarbons having boiling points higherthan 350 F., the most beneficial results being obtained fromhydrocarbons having boiling points ranging from 450 F. to 700 F. Thevalve 8 in the vapor pipe 6is adjusted to obtain the desired pressure inthe still, heat exchanger A and reflux condenser 5. The pressure mayrange from 50 to 150 pounds per square inch, or even higher, but it ispreferably maintained atabout 85 pounds per square inch. The contents ofthe still are preferably subjected to such a high degree of heat thatthe hydrocarbon liquid will vaporize very rapidly. This tempera'- turemay range from about 600 F. to 800 F., and is preferably about 725 F.

Owing to the intense heat and the rapid vaporization, a large volumel ofunconverted, or partially converted, hydrocarbons will flow from thestillv 1 to the heat exchanger Jcondensing the previously vaporizedfractions having relatively high boiling points. By bubbling the vaporthrough a relatively cool liquid, as herein shown, all of the vapor isvery effectively subjected to the action of the cool liquid, and theheaviest fractions are condensed and preventedfrom passing to the maincondenser. The heat exchanger thereforeY constitutes a highly efficientcondenser for the high boiling point fractions.

The hottest portion of the liquid overflows from the heat exchanger a-ndpasses through the overflow pipe llto the still l. This overfiowingliquid flows by gravity to the still, the heat exchanger being higherthan the still. To prevent the vapor from fiowing through the overflowpipe 11, the discharge end of said pipe is preferably located near thebottom ofthe'still. It will be observed that the body of liquid abovethe discharge end of pipe 11, is vdeeper than the body of liquid abovethe vapor discharging member 9.

Thefresh charge of relatively cool oil, fiowing from the pipe 14,commingles with the hot condensate in the heat exchanger A, and is alsosubjected to the high temperature of the hot vapors bubbling throughthe` liquidvmixture in the heat exchanger. The fresh charge of oil isthus subjected to a very high temperature, and thoroughly heated, beforeit overflows at the surface of the liquid body in the heat exchanger.

The reflux condensate,fflowing from the condenser 5, passes through thepipe 4 and commingles with the liquid in the heat exchanger, thiscondensate being heated before it overfiows to the still.

The desirable low boiling point fractions flow from the reiiuxcondenser\5, through the vapor pipe 6, andl into the main condenser 7, where theyare condensed to form the low boiling point product.

It will now be understood that the hot vapor, bubbling through thehydrocarbon liquid in the heat exchanger, is cooled so as to separatethe high boiling oint fractions from the lighter ractions; t e hotcondensate returns freely to the still; the fresh charge' of oil isthoroughly'heated by the vapor and also by the hot condensate; the

heat exchanger also serves as means for heating the refiux condensatefiowing from the condenser 5, and although the vapor is bubbled throughthe liquid, it will be apparent that the heat exchanger will perform itsseveral functions while maintained under the high pressure necessary tocrack petroleum hydrocarbons.

The method herein disclosed is claimed in an application for pttentfiled by me on May 5, 1917, Serial o. 166,524.

I claim:-

1. In an apparatus for treating hydrocar- A bons, a still, a heatexchanger comprising a reservoir wherein a body of hydrocarbon Y areflux condenser arranged to receive the p vapor bubbling from thesurface of said liquid, said reflux condenser bemg positioned to returnits condensate to said reservoir,

a main condenser communicating with the reflux condenser, said reservoirbeing higher than the still, and an overflow conductor whereby heatedrefiux condensate is permitted to flow, by gravity, from the top of theliquid in said reservoir to the still.

2. In an apparatus for treating hydroi carbons, a still, a heatexchanger compris- Aing a reservoir wherein a body of 'hydrocarbonliquid is maintained and 'a vapor conductor whereby vapor passing fromthe still is discharged into said body of hydrocarbon liquid, said vaporconductor having a perforated discharge member submerged in said liquidto provide for the discharge of numerous small streams of hot vapor intothe liquid, a reflux condenser arranged to receive the vapor bubblingfrom the surface of said liquid, said reflux condenser being positionedto return its condensate to said reservoir, a main condensercommunicating

